title: Short-term, daily intake of yogurt containing Bifidobacterium animalis ssp. lactis Bf-6 (LMG 24384) does not affect colonic transit time in women.
abstract: The present study investigated the effect of Bifidobacterium animalis ssp. lactis Bf-6 (LMG 24 384) (Bf-6)-supplemented yogurt on colonic transit time (CTT). A triple-blinded, randomised, placebo-controlled, two-period cross-over trial was conducted with sixty-eight women with a self-reported history of straining during bowel movements or hard or lumpy stools in the past 2 years. As per regulatory requirements for probiotic studies, eligible women were generally healthy and not actively constipated at the time of enrolment. Participants consumed both Bf-6 and placebo yogurts for 14 d each in a randomised order, with a 6-week washout period between the treatments. The primary outcome, CTT, was assessed via Sitz marker X-rays. The average CTT was 42·1 h for the active period and 43·3 h for the control period (mean difference 1·2 h, 95 % CI - 4·9, 7·4). Since the statistical tests for the cross-over study implied that the mean CTT for the active and control periods in period 2 were biased, the standard protocol suggests examining the results of only period 1 as a traditional randomised controlled trial. This showed that the mean CTT was 35·2 h for the active period v. 52·9 h for the control period (P= 0·015). Bootstrapping demonstrated that both the mean and median differences remained significant (P= 0·016 and P= 0·045, respectively). Few adverse events were noted, with no differences among the active and control periods. The paired analysis showed no differences between the active and control periods during the cross-over trial. Further trials should be conducted in populations with underlying problems associated with disordered transit to determine the potential value of probiotic supplementation more accurately.
authors.affiliation: Department of Family Medicine, Georgetown University Medical Center, 240 Building D, 4000 Reservoir Road NW, Washington, DC 20007-2145, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Merenstein
authors.affiliation: Department of Mathematics, UPMC, St. Margaret Hospital, Duquesne University, Pittsburgh, PA, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: D'Amico
authors.affiliation: Division of Gastroenterology, Department of Medicine, Georgetown University Medical Center, Washington, DC, USA.
authors.forename: Caren
authors.initials: C
authors.lastname: Palese
authors.affiliation: Department of Family Medicine, Georgetown University Medical Center, 240 Building D, 4000 Reservoir Road NW, Washington, DC 20007-2145, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Hahn
authors.affiliation: Department of Family Medicine, Georgetown University Medical Center, 240 Building D, 4000 Reservoir Road NW, Washington, DC 20007-2145, USA.
authors.forename: Jessy
authors.initials: J
authors.lastname: Sparenborg
authors.affiliation: Department of Family Medicine, Georgetown University Medical Center, 240 Building D, 4000 Reservoir Road NW, Washington, DC 20007-2145, USA.
authors.forename: Tina
authors.initials: T
authors.lastname: Tan
authors.affiliation: Division of Gastroenterology, Department of Medicine, Georgetown University Medical Center, Washington, DC, USA.
authors.forename: Hillary
authors.initials: H
authors.lastname: Scott
authors.affiliation: Cargill, Inc., Wayzata, MN, USA.
authors.forename: Kayla
authors.initials: K
authors.lastname: Polzin
authors.affiliation: Cargill, Inc., Wayzata, MN, USA.
authors.forename: Lore
authors.initials: L
authors.lastname: Kolberg
authors.affiliation: Department of Food Science, The Pennsylvania State University, University Park, PA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Roberts
mesh_terms: D000293:Adolescent; D000328:Adult; D001644:Bifidobacterium / Q000502:physiology*; D003106:Colon / Q000502:physiology; D018592:Cross-Over Studies; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D019936:Probiotics; D015014:Yogurt / Q000382:microbiology*; D055815:Young Adult